Apparatus and methods for delivering therapeutic agents

ABSTRACT

The present embodiments provide apparatus and methods suitable for delivering a therapeutic agent to a target site. The apparatus generally comprises at least one container for holding a therapeutic agent, and a pressure source for facilitating delivery of the therapeutic agent. In one embodiment, the pressure source may be placed in selective fluid communication with a proximal region of the container and fluid from the pressure source may flow through at least a portion of the container to urge the therapeutic agent through container towards the target site. In an alternative embodiment, the container and the pressure source may be coupled to first and second inlet ports of a connecting member, respectively, such that the therapeutic agent flows through an outlet port of the connecting member and towards the target site.

PRIORITY CLAIM

The present patent document is a divisional application that claims thebenefit of priority under 35 U.S.C. § 121 of U.S. patent applicationSer. No. 12/435,574, filed May 5, 2009, which claims the benefit ofpriority of U.S. Provisional Application Ser. No. 61/050,906, filed May6, 2008, both disclosures of which are hereby incorporated by referencein their entireties.

BACKGROUND

The present embodiments relate generally to medical devices, and moreparticularly, to apparatus and methods for delivering therapeutic agentsto a target site.

There are several instances in which it may become desirable tointroduce therapeutic agents into the human or animal body. For example,therapeutic drugs or bioactive materials may be introduced to achieve abiological effect. The biological effect may include an array oftargeted results, such as inducing hemostasis, sealing perforations,reducing restenosis likelihood, or treating cancerous tumors or otherdiseases.

Many of such therapeutic agents are injected using an intravenous (IV)technique and via oral medicine. While such techniques permit thegeneral introduction of medicine, in many instances it may be desirableto provide localized or targeted delivery of therapeutic agents, whichmay allow for the guided and precise delivery of agents to selectedtarget sites. For example, localized delivery of therapeutic agents to atumor may reduce the exposure of the therapeutic agents to normal,healthy tissues, which may reduce potentially harmful side effects.

Localized delivery of therapeutic agents has been performed usingcatheters and similar introducer devices. By way of example, a cathetermay be advanced towards a target site within the patient, then thetherapeutic agent may be injected through a lumen of the catheter to thetarget site. Typically, a syringe or similar device may be used toinject the therapeutic agent into the lumen of the catheter. However,such a delivery technique may result in a relatively weak stream of theinjected therapeutic agent.

Moreover, it may be difficult or impossible to deliver therapeuticagents in a targeted manner in certain forms, such as a powder form, toa desired site. For example, if a therapeutic powder is held within asyringe or other container, it may not be easily delivered through acatheter to a target site in a localized manner that may also reducepotentially harmful side effects.

SUMMARY

The present embodiments provide apparatus and methods suitable fordelivering a therapeutic agent to a target site. The apparatus generallycomprises at least one container for holding a therapeutic agent, and apressure source for facilitating delivery of the therapeutic agent.

In one embodiment, the pressure source may be placed in selective fluidcommunication with a proximal region of the container. Fluid from thepressure source may flow through at least a portion of the container tourge the therapeutic agent through a distal region of the container andtowards the target site.

At least one tube member, such as a catheter, may be used to facilitatedelivery of the therapeutic agent from the container to the target site.The tube member may be placed in fluid communication with the distalregion of the container. In use, fluid from the pressure source urgesthe therapeutic agent through the distal region of the container,through the tube member, and then distally towards the target site.

The pressure source may comprise a compressed gas dispenser. Tubing maybe disposed between the pressure source and the container, andoptionally, a pressure relief valve may be disposed between the pressuresource and the container. The pressure relief valve may ensure that thefluid from the pressure source flows through the container at apredetermined pressure.

In various other embodiments, a connecting member having first andsecond inlet ports and an outlet port is disclosed. The container andthe pressure source may be coupled to the first and second inlet portsof the connecting member, respectively. In use, the provision of fluidfrom the pressure source through the second inlet port may suction thetherapeutic agent from the container in a direction through the firstinlet port. The fluid and the therapeutic agent then may flow throughthe outlet port of the connecting member and towards the target site. Inthis embodiment, at least one tube member may be coupled to the outletport of the connecting member to facilitate delivery of the therapeuticagent from the connecting member to the target site.

In any of the embodiments disclosed, the distal region of the tubemember may comprise an anti-reflux valve to inhibit flow of foreignsubstances, such as blood, proximally back into the system. The tubemember also may be used in conjunction with a needle and may beconfigured to be delivered through a working lumen of an endoscope orsimilar device.

Other systems, methods, features and advantages of the invention willbe, or will become, apparent to one with skill in the art uponexamination of the following figures and detailed description. It isintended that all such additional systems, methods, features andadvantages be within the scope of the invention, and be encompassed bythe following claims.

BRIEF DESCRIPTION OF THE DRAWINGS

The invention can be better understood with reference to the followingdrawings and description. The components in the figures are notnecessarily to scale, emphasis instead being placed upon illustratingthe principles of the invention. Moreover, in the figures, likereferenced numerals designate corresponding parts throughout thedifferent views.

FIG. 1 is a schematic view of apparatus in accordance with a firstembodiment.

FIG. 2 is a side view illustrating selected components of an exemplaryhigh pressure fluid source.

FIG. 3 is a perspective view of the distal end of an exemplaryend-viewing endoscope that may be used in conjunction with the system ofFIG. 1.

FIG. 4 is a perspective view of the distal end of an exemplaryside-viewing endoscope that may be used in conjunction with the systemof FIG. 1.

FIG. 5 is a schematic view of apparatus in accordance with analternative embodiment.

FIG. 6 is a schematic view of apparatus in accordance with a furtheralternative embodiment.

FIG. 7 is a schematic view of apparatus in accordance with yet a furtheralternative embodiment.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

In the present application, the term “proximal” refers to a directionthat is generally towards a physician during a medical procedure, whilethe term “distal” refers to a direction that is generally towards atarget site within a patient's anatomy during a medical procedure.

Referring now to FIG. 1, a first embodiment of a system suitable fordelivering one or more therapeutic agents is shown. In this embodiment,the system 20 comprises at least one container 30 that is configured tohold a therapeutic agent 38, and further comprises at least one pressuresource 50. At least one connecting member 70 may be placed in fluidcommunication with the container 30 and the pressure source 50, asexplained in further detail below.

The container 30 may comprise any suitable size and shape for holding atherapeutic agent 38. In one embodiment, the container 30 may comprise asyringe having a reservoir 32. A plunger 40 having a main body 42, aproximal handle 43, and a distal head member 44 may be disposed forlongitudinal movement within the reservoir 32, preferably in a mannersuch that the distal head member 44 forms a substantial sealingengagement with an inner surface of the container 30.

The container 30 may comprise a hollow proximal region 34, through whichthe therapeutic agent 38 and the plunger 40 may be loaded, as shown inFIG. 1. The container 30 further may comprises a distal region 36 thatis configured to be coupled to a first inlet port 72 associated with theconnecting member 70, thereby enabling fluid communication between thecontainer 30 and the connecting member 70.

The container 30 also may comprise measurement indicia 39, which allow auser to determine a quantity of the therapeutic agent 38 that is heldwithin the container 30. Optionally, a valve member 47 may be disposedbetween the reservoir 32 of the container 30 and the connecting member70, as shown in FIG. 1, to selectively permit and inhibit fluidcommunication between the container 30 and the connecting member 70, asdescribed in greater detail below.

The pressure source 50 may comprise one or more components capable ofproducing or furnishing a fluid having a desired pressure. In oneembodiment, the pressure source 50 may comprise a pressurized fluid,such as a liquid or gas. For example, as shown in FIG. 2, the pressuresource 50 may comprise a housing 51 that covers a pressurized fluidcartridge 52 of a selected gas or liquid, such as carbon dioxide,nitrogen, or any other suitable gas or liquid that may be compatiblewith the human body. The pressurized fluid cartridge 52 may contain thegas or liquid at a relatively high, first predetermined pressure, forexample, around 1,800 psi inside of the cartridge. The fluid may flowfrom the pressurized fluid cartridge 52 through a pressure regulator,such as regulator valve 58 having a pressure outlet 59, as depicted inFIGS. 1-2, which may reduce the pressure to a lower, secondpredetermined pressure. Solely by way of example, the secondpredetermined pressure may be in the range of about 30 to about 80 psi,although any suitable pressure may be provided for the purposesdescribed below.

An actuator, such as a button, may be used to selectively actuate thepressure source 50. The pressurized fluid may flow from the pressurizedfluid cartridge 52, and subsequently through the regulator valve 58using an adapter 54. The adapter 54 may be configured to be sealinglycoupled to the pressurized fluid cartridge 52, as shown in FIG. 2.Further, the adapter 54 may be coupled to tubing 56, which allows thepressurized fluid to flow into the regulator valve 58. A proximal end 62of a different tubing 60 is adapted to be coupled to the regulator valve58, as shown in FIG. 2, thereby enabling the pressurized fluid to flowthrough the regulator valve 58 and into the tubing 60 at the lower,second predetermined pressure.

The pressure source 50 optionally may comprise one or more commerciallyavailable components. Solely by way of example, the pressurized fluidcartridge 52 may comprise a disposable carbon dioxide cartridge, such asthe Visage® commercial dispenser manufactured by Helen of Troy®, ElPaso, Tex. The pressure source 50 therefore may comprise original orretrofitted components capable of providing a fluid or gas into thetubing 60 at a desired regulated pressure.

Referring still to FIG. 1, the connecting member 70 of the system 20 maycomprise multiple ports configured to selectively permit and inhibitfluid communication between the various components. In one embodiment,the connecting member 70 comprises first and second inlet ports 72 and74 and an outlet port 76. As noted above, the distal region 36 of thecontainer 30 may be coupled to the first inlet port 72 of the connectingmember 70, thereby enabling selective fluid communication between thecontainer 30 and the connecting member 70, as depicted in FIG. 1. Anysuitable coupling mechanism may be employed, for example, the distalregion 36 of the container 30 may be configured to form a frictional fitwith the first inlet port 72, or may comprise a threaded engagement orsimilar coupling arrangement. Similarly, a distal end 64 of the tubing60 may be coupled to the second inlet port 74 of the connecting member70 using any suitable coupling mechanism or arrangement.

In the embodiment of FIG. 1, the second inlet port 74 and the outletport 76 are generally aligned with a longitudinal axis L of theconnecting member 70, while the first inlet port 72 is disposed at anangle α₁ with respect to the longitudinal axis L. However, as will bedescribed further below, the connecting member may employ differentshapes such that various components may be disposed at different angleswith respect to the connecting member.

The system 20 further may comprise one or more tube members fordelivering the therapeutic agent 38 to a target site. For example, thetube member may comprise a catheter 90 having a proximal end 92 that maybe placed in fluid communication with the outlet port 76 of theconnecting member 70 using a suitable coupling mechanism or arrangement.The catheter 90 further comprises a distal end 94 that may facilitatedelivery of the therapeutic agent 38 to a target site, as set forthbelow. The catheter 90 may comprise a flexible, tubular member that maybe formed from one or more semi-rigid polymers. For example, thecatheter may be manufactured from polyurethane, polyethylene,tetrafluoroethylene, polytetrafluoroethylene, fluorinated ethylenepropylene, nylon, PEBAX or the like.

The system 20 further may comprise a needle 95 suitable for penetratingtissue. As shown in the embodiment of FIG. 1, the needle 95 may becoupled to the distal end 94 of the catheter 90 to form a sharp, distalregion configured to pierce through a portion of a patient's tissue, orthrough a lumen wall to perform a translumenal procedure. In FIG. 1, theneedle 95 may be formed as an integral component with the catheter 90,i.e., such that distal movement of the catheter 90 causes distaladvancement of the needle 95. In this embodiment, a relatively sharpneedle tip may be affixed to the distal tip of the catheter 90, e.g.,using an adhesive, to form a needle-shaped element at the distal end ofthe catheter. Alternatively, a separate needle configured to be insertedthrough a lumen of the catheter 90 may be employed.

In operation, the system of FIG. 1 may be used to deliver thetherapeutic agent 38 to a target site within a patient's body. In afirst step, the distal end 94 of the catheter 90 may be positioned inrelatively close proximity to the target site. The catheter 90 may beadvanced to the target site using an open technique, a laparoscopictechnique, an intraluminal technique, using a gastroenterology techniquethrough the mouth, colon, or using any other suitable technique.

The catheter 90 may comprise one or more markers (not shown), which maybe disposed near the distal end of the catheter 90. The markers may beconfigured to be visualized under fluoroscopy or other imagingtechniques to facilitate location of the distal end 94 of the catheter90. If the needle 95 is integral to the catheter 90, the needle 95 alsomay be visualized using the imaging techniques, thereby allowingplacement of the distal end 94 of the catheter 90 in close proximity tothe target site. If desired, the catheter 90 may be advances through aworking lumen of an endoscope, as explained in further detail in FIGS.3-4 below.

When the catheter 90 is positioned at the desired location, the pressuresource 50 may be actuated. For example, a suitable actuator may becoupled to the pressurized fluid cartridge 52 to release a relativelyhigh pressure fluid. As noted above, the pressurized fluid may flowthrough a regulator valve 58 and through the tubing 60, as depicted inFIG. 1. Fluid injected through the tubing 60 may flow at a desiredpressure and rate. For example, the regulator valve 58 may automaticallyset the pressure for fluid flow, or alternatively, a control mechanismcoupled to the pressurized fluid cartridge 52 and/or the regulator valve58 may be activated by a user to set the desired pressure for fluid flowinto the tubing 60. Such a control mechanism also may be used tovariably permit fluid flow into the tubing 60, e.g., fluid from thepressurized fluid cartridge 52 may flow into the tubing 60 at a desiredtime interval, for example, a predetermined quantity of fluid persecond. Moreover, the control mechanism may be pre-programmed to delivera predetermined amount of the therapeutic agent, depending on the type,viscosity, and other properties of the agent. Empirical information,such as a table of pressure, time and delivered quantity, may be storedand used for the different agents or procedures.

Fluid from the pressure source 50 flows through the tubing 60, throughthe second inlet port 74 of the connecting member 70, and then throughthe outlet port 76 of the connecting member 70 and through a lumen ofthe catheter 90. Fluid may exit the distal end 94 of the catheter 90,for example, through a bore formed in the needle 95.

As fluid from the pressure source 50 passes through the connectingmember 70, a localized low pressure system will be provided in thevicinity of the second inlet port 72 in accordance with Bernoulli'sprinciple of fluid dynamics. The low pressure system formed by thepresence of the pressurized fluid passing through the connecting member70 will form a strong suction force when it passes by the second inletport 72. As a result, the therapeutic agent 38 may be suctioned out ofthe reservoir 32 of the container 30 and through the second inlet port72. Moreover, the therapeutic agent 38 may be carried through the outletport 76 of the connecting member 70 by the pressurized fluid, andsubsequently through the catheter 90, thereby delivering the therapeuticagent 38 to the target site at a desired pressure.

The therapeutic agent 38 may be drawn out of the reservoir 32 by themere presence of the pressurized fluid flow through the connectingmember 70, i.e., with minimal or no user intervention. In thisembodiment, the user simply may load the desired therapeutic agent 38into the reservoir 32, then load the plunger 40 into the proximal region34 of the container 30. The provision of the pressurized fluid flowthrough the connecting member 70 may suction the therapeutic agent 38from the reservoir 32 and may urge the plunger 40 in a distal directionuntil the contents of the container 30 are dispensed.

In addition to the automatic withdrawal of the therapeutic agent 38 fromthe container 30 in accordance with Bernoulli's principle, a user maymanually actuate the proximal handle 43 of the plunger 40 to dispensethe therapeutic agent 38. For example, in this instance, after a userhas loaded a desired amount of the therapeutic agent 38 into thereservoir 32, the user may manually actuate the proximal handle 43 ofthe plunger 40 to dispense the therapeutic agent 38 from the container30 and at least partially into interior regions of the connecting member70 and/or the catheter 90. The plunger 40 may be manually actuated inthis manner before, during or after the pressure source 50 has beenactuated to deliver pressurized fluid through the connecting member 70and the catheter 90.

As noted above, a valve member 47 optionally may be disposed between thereservoir 32 of the container 30 and the connecting member 70, as shownin FIG. 1. A user may selectively actuate the valve member 47 toperiodically permit and inhibit fluid communication between thecontainer 30 and the connecting member 70. The valve member 47 also mayserve as a “shut-off” safety mechanism to inhibit withdrawal of thetherapeutic agent 38 from the reservoir 32, even when pressurized fluidis flowing through the connecting member 70.

As noted above, a control mechanism coupled to the pressure source 50may variably permit fluid flow into the tubing 60 from the pressurizedfluid cartridge 52 at a desired time interval, for example, apredetermined quantity of fluid per second. In this manner, pressurizedfluid may flow through the connecting member 70 periodically, and thetherapeutic agent 38 may be suctioned from the reservoir 32 anddelivered to a target site at a predetermined interval or otherwiseperiodic basis.

The system 20 may be used to delivery the therapeutic agent 38 in a widerange of procedures and the therapeutic agent 38 may be chosen toperform a desired function upon ejection from the distal end 94 of thecatheter 90. Solely by way of example, and without limitation, theprovision of the therapeutic agent 38 may be used for providinghemostasis, closing perforations, performing lithotripsy, treatingtumors and cancers, treat renal dialysis fistulae stenosis, vasculargraft stenosis, and the like. The therapeutic agent 38 can be deliveredduring procedures such as coronary artery angioplasty, renal arteryangioplasty and carotid artery surgery, or may be used generally fortreating various other cardiovascular, respiratory, gastroenterology orother conditions. The above-mentioned systems also may be used intransvaginal, umbilical, nasal, and bronchial/lung related applications.

For example, if used for purposes of hemostasis, thrombin, epinephrine,or a sclerosant may be provided to reduce localized bleeding. Similarly,if used for closing a perforation, a fibrin sealant may be delivered toa localized lesion. In addition to the hemostatic properties of thetherapeutic agent 38, it should be noted that the relatively highpressure of the fluid and therapeutic agent, by itself, may act as amechanical tamponade by providing a compressive force, thereby reducingthe time needed to achieve hemostasis.

The therapeutic agent 38 may be selected to perform one or more desiredbiological functions, for example, promoting the ingrowth of tissue fromthe interior wall of a body vessel, or alternatively, to mitigate orprevent undesired conditions in the vessel wall, such as restenosis.Many other types of therapeutic agents 38 may be used in conjunctionwith the system 20.

The therapeutic agent 38 may be delivered in any suitable form. Forexample, the therapeutic agent 38 may comprise a powder, liquid, gel,aerosol, or other substance. Advantageously, the pressure source 50 mayfacilitate delivery of the therapeutic agent 38 in any one of theseforms.

The therapeutic agent 38 employed also may comprise an antithrombogenicbioactive agent, e.g., any bioactive agent that inhibits or preventsthrombus formation within a body vessel. Types of antithromboticbioactive agents include anticoagulants, antiplatelets, andfibrinolytics. Anticoagulants are bioactive materials which act on anyof the factors, cofactors, activated factors, or activated cofactors inthe biochemical cascade and inhibit the synthesis of fibrin.Antiplatelet bioactive agents inhibit the adhesion, activation, andaggregation of platelets, which are key components of thrombi and playan important role in thrombosis. Fibrinolytic bioactive agents enhancethe fibrinolytic cascade or otherwise aid in dissolution of a thrombus.Examples of antithrombotics include but are not limited toanticoagulants such as thrombin, Factor Xa, Factor VIIa and tissuefactor inhibitors; antiplatelets such as glycoprotein IIb/IIIa,thromboxane A2, ADP-induced glycoprotein IIb/IIIa, and phosphodiesteraseinhibitors; and fibrinolytics such as plasminogen activators, thrombinactivatable fibrinolysis inhibitor (TAFI) inhibitors, and other enzymeswhich cleave fibrin.

Additionally, or alternatively, the therapeutic agent 38 may includethrombolytic agents used to dissolve blood clots that may adverselyaffect blood flow in body vessels. A thrombolytic agent is anytherapeutic agent that either digests fibrin fibers directly oractivates the natural mechanisms for doing so. Examples of commercialthrombolytics, with the corresponding active agent in parenthesis,include, but are not limited to, Abbokinase (urokinase), AbbokinaseOpen-Cath (urokinase), Activase (alteplase, recombinant), Eminase(anitstreplase), Retavase (reteplase, recombinant), and Streptase(streptokinase). Other commonly used names are anisoylatedplasminogen-streptokinase activator complex; APSAC; tissue-typeplasminogen activator (recombinant); t-PA; rt-PA. While a few exemplarytherapeutic agents 38 have been listed, it will be apparent thatnumerous other suitable therapeutic agents may be used in conjunctionwith the system 20 and delivered through the catheter 90.

Advantageously, the system 20 permits localized delivery of a desiredquantity of the therapeutic agent 38 at a desired pressure via thepressure source 50. Since the distal end 94 of the catheter 90 may beplaced in relatively close proximity to a target site, the system 20provides significant advantages over therapeutic agents delivered orallyor through an IV system and may reduce accumulation of the therapeuticagent 38 in healthy tissues, thereby reducing side effects. Moreover,the delivery of the therapeutic agent 38 to the target site is performedin a relatively fast manner due to the relatively high pressure of thefluid, thereby providing a prompt delivery to the target site comparedto previous devices.

Further, if the optional needle 95 is employed, the system 20advantageously may be used to both perforate tissue at or near a targetsite, then deliver the therapeutic agent 38 at a desired pressure in themanner described above. For example, the needle 95 may comprise anendoscopic ultrasound (EUS) needle. Accordingly, in one exemplarytechnique, a sharpened tip of the needle 95 may be capable of puncturingthrough an organ or a gastrointestinal wall or tissue, so that thetherapeutic agent 38 may be delivered at a predetermined pressure invarious bodily locations that may be otherwise difficult to access. Oneor more delivery vehicles, such as an endoscope or sheath, may beemployed to deliver the catheter 90 to a target site, particularly ifthe distal end 94 of the catheter 90 comprises the optional needle 95.

Referring now to FIGS. 3-4, exemplary endoscopes that may be used inconjunction with the system 20 are described. In FIG. 3, an end-viewingendoscope 150 comprises optical elements 173 and 174 disposed on thedistal end surface of the endoscope, which employ fiber optic componentsfor illuminating and capturing an image distal to the endoscope.Further, a working channel 161 extends through the distal end surface ofthe endoscope 150, as shown in FIG. 3. The working channel 161 may besized to accommodate the catheter 90 therein for purposes oflongitudinally advancing the catheter 90 to the target site. As shown,one auxiliary lumen 162 also optionally may be provided, althoughgreater or fewer lumens/channels may be employed.

The endoscope 150 may be advanced through a bodily lumen such as thealimentary canal to a position proximate the target location. Thecatheter 90 then may be advanced through the working lumen 161 of theendoscope 150. If the needle 95 is employed, a sharpened tip 96 of theneedle 95 may extend distal to the endoscope 150, as shown in FIG. 3,and may be used to puncture through an organ or a gastrointestinal wallor tissue. At this time, the therapeutic agent 38 may be deliveredthrough the catheter 90, then through a bore 97 in the needle 95, in themanner described above.

In FIG. 4, a side-viewing endoscope 150′ is similar to the end-viewingendoscope 150, with the main exception that optical elements 173′ and174′ are disposed on a side surface of the endoscope 150′ and capable ofcapturing an image to the side of the endoscope. The endoscope 150′preferably comprises a working channel 161′, which is sized toaccommodate the catheter 90 therein for purposes of longitudinallyadvancing the catheter to a target site. A guiding channel 165 may beformed near the distal surface of the endoscope 150′ to cause componentsadvanced through the working channel 161′ to exit at a predeterminedangle with respect to a longitudinal axis of the endoscope 150′. It willbe apparent that while one working channel 161′ is shown, the endoscope150′ may comprise at least one more additional lumen or channel, such asan auxiliary lumen.

Referring now to FIG. 5, an alternative system 220 for deliverytherapeutic agents is similar to system 20 of FIG. 1, both in structureand general operation, with main exceptions noted below. In FIG. 5, thealternative system 220 comprises a generally Y-shaped connecting member270, which has a slightly different shape relative to the connectingmember 70 of FIG. 1. Specifically, the connecting member 270 has firstand second inlet ports 272 and 274, respectively, and an outlet port276. The outlet port 276 may be aligned with a longitudinal axis L, asshown in FIG. 5. The first inlet port 272 may be disposed at an angle α₁with respect to the axis of the outlet port 276, while the second inletport 274 may be disposed at an angle α₂ with respect to the outlet port276, as depicted in FIG. 5. The angles α₁ and α₂ are depicted as beingsubstantially identical in FIG. 5, at about 25-45 degrees, which mayfacilitate mixing and/or flow of the contents through the connectingmember 270 and out of the outlet port 276. However, it will be apparentthat any suitable angle may be employed and that the angles α₁ and α₂may comprise different angles.

Referring now to FIG. 6, an alternative system 320 for deliverytherapeutic agents is shown. The alternative system 320 is similar tosystem 20 of FIG. 1, both in structure and general operation, with amain exception that alternative connecting member 370 has a first inletport 372 aligned with the longitudinal axis L, and a second inlet port374 disposed at an angle α₂ with respect to the outlet port 376.Further, in this embodiment, the second inlet port 374 is placed incloser proximity to the outlet port 376, in relation to the positioningof the first inlet port 372, as shown in FIG. 6. In this embodiment,like the others described above, the fluid from the pressure source 50passes through the second inlet port 374 and into the alternativeconnecting member 370 to create a localized low pressure system in thevicinity of the first inlet port 372. The low pressure system will forma strong suction force to suction the therapeutic agent 38 out of thereservoir 32, through the first inlet port 372 and through the catheter90.

Referring now to FIG. 7, an alternative system 420 for deliverytherapeutic agents is described. The alternative system 420 is similarto system 20 of FIG. 1 in general operation, with main exceptions notedbelow. Notably, in the embodiment of FIG. 7, fluid from the pressuresource 50 may be passed directly through a proximal region 434 of thecontainer 430. In this embodiment, the plunger of the container may beomitted. A therapeutic agent 438 is provided within a reservoir 432using measurement indicia 439. Tubing 62 may be coupled between thepressure source 50 and the proximal region 434 of the container 430.When the pressure source 50 is actuated, a high pressure fluid may flowdirectly through the container 430 to urge the therapeutic agent 438 outof a distal region 436 of the container 430 and into the catheter 90.

Additionally, in the embodiment of FIG. 7, a pressure relief valve 470may be disposed between the pressure source 50 and the container 430.The pressure relief valve 470 may be similar to the regulator valve 58of FIG. 1, and may comprise first and second ports 471 and 472 having anoutlet valve 473 disposed therebetween. In operation, if fluid from thepressure source 50 exceeds a predetermined pressure, the pressure reliefvalve 470 may reduce the pressure that flows out of the second port 472and into the container 430.

Finally, the alternative system 420 further comprises an anti-refluxvalve 480 coupled to the distal end 94 of the catheter 90, as shown inFIG. 7. In use, the anti-reflux valve 480 may be configured to preventblood or other foreign fluids from entering a distal opening 482 of thevalve, and then flowing proximally into the catheter 90, which may leadto complications such as occlusion in the system 420. While theanti-reflux valve 480 is shown in use in the embodiment of FIG. 7, itwill be apparent that it may be used in lieu of the needle 95 inconjunction with the embodiments of FIGS. 1, 5 and 6. Conversely, theneedle 95 of the above-mentioned embodiments may be coupled to thedistal end 94 of the catheter 90 in the embodiment of FIG. 7.

While various embodiments of the invention have been described, theinvention is not to be restricted except in light of the attached claimsand their equivalents. Moreover, the advantages described herein are notnecessarily the only advantages of the invention and it is notnecessarily expected that every embodiment of the invention will achieveall of the advantages described.

I claim:
 1. A method suitable for delivering at least one therapeuticagent to a target site, the method comprising: providing at least onecontainer having proximal and distal regions, wherein the containerholds a therapeutic agent; placing a pressure source in selective fluidcommunication with the proximal region of the container; actuating thepressure source to cause fluid to flow through at least a portion of thecontainer to both a) generate a mixture of fluid from the pressuresource and the therapeutic agent and b) urge the mixture of the fluidfrom the pressure source and the therapeutic agent concurrently throughthe distal region of the container and then through a tube member in adistal direction towards the target site; and selectively inhibitingflow of the mixture of the fluid from the pressure source and thetherapeutic agent using a valve having a proximal end and a distal end,wherein the proximal end and the distal end of the valve are disposeddistal to the container and proximal to the tube member.
 2. The methodof claim 1, wherein the therapeutic agent comprises a powder.
 3. Themethod of claim 1, wherein the pressure source comprises a compressedgas dispenser.
 4. The method of claim 1, further comprising placing atube between the pressure source and the container.
 5. The method ofclaim 1, further comprising placing a pressure relief valve between thepressure source and the container.
 6. A method suitable for deliveringat least one therapeutic agent to a target site, the method comprising:positioning a distal end of a tube member adjacent to a target site,wherein a proximal end of the tube member is coupled to a distal regionof a container holding a therapeutic agent; actuating a pressure sourceto cause fluid to flow through a proximal region of the container toboth a) generate a mixture of the fluid from the pressure source and thetherapeutic agent and b) urge the mixture of the fluid from the pressuresource and the therapeutic agent to flow concurrently through the distalregion of the container and then through the tube member in a distaldirection towards the target site; and selectively inhibiting flow ofthe mixture of the fluid from the pressure source and the therapeuticagent using a valve having a proximal end and a distal end, wherein theproximal end and the distal end of the valve are disposed distal to thecontainer and proximal to the tube member.
 7. The method of claim 6,wherein the therapeutic agent comprises a powder.
 8. The method of claim6, wherein the pressure source comprises a compressed gas dispenser. 9.The method of claim 6 further comprising: providing tubing disposedbetween the pressure source and the container; and providing a pressurerelief valve disposed between the pressure source and the container. 10.A method suitable for delivering at least one therapeutic agent to atarget site, the method comprising: placing a pressure source inselective fluid communication with a proximal region of a container,wherein the container holds a therapeutic agent; positioning a distalend of a tube member adjacent to a target site, wherein a proximal endof the tube member is coupled to a distal region of the container;actuating the pressure source to cause fluid to flow through at least aportion of the container to both a) generate a mixture of fluid from thepressure source and the therapeutic agent and b) urge the mixture fromthe pressure source and the therapeutic agent concurrently through thedistal region of the container and then through the tube member in adistal direction towards the target site; wherein the therapeutic agentcomprises a powder; and wherein the pressure source comprises acompressed gas dispenser.
 11. The method of claim 10, further comprisingselectively inhibiting flow of the mixture of the fluid from thepressure source and the therapeutic agent using a valve disposedproximal to the tube member.
 12. The method of claim 10, furthercomprising placing a tube between the pressure source and the container.13. The method of claim 10, further comprising placing a pressure reliefvalve between the pressure source and the container.